The tiny amounts of methane found by the rover are of particular interest to planetary scientists. The fact is that it can indicate life below the surface of the planet.
Back in 2004, NASA scientists announced that they had found traces of gas in the Martian atmosphere. It is possible that the methane found on the Red Planet appeared as a result of geological processes, but it can equally be evidence of the existence of microbial life in the soil of an alien world.
However, in the years since this first discovery, a mystery has arisen associated with the presence of gas. Namely, why are some instruments capable of detecting traces of methane while others that are theoretically capable of not?
For example, while making its way through Gale Crater, NASA’s Curiosity rover was able to detect traces of gas using its Tunable Laser Spectrometer (TLS).
Typically, TLS records about half of methane per billion in atmospheric volume, with periodic unexplained spikes of up to 20 ppb. When the European Space Agency’s (ESA) Trace Gas Orbiter arrived on Mars in 2016, scientists believed it would confirm Curiosity’s observations. But that did not happen.
Why is this happening?
A scientist from the University of York in Toronto, John Moores, proposed his hypothesis. Moores, who worked with the NASA team, suggested that the discrepancies in the measurements were caused by the time of the Martian day in which they were made.
The American device operated on Martian nights when the rest of the Curiosity equipment was dormant. At night, calm reigns on Mars, and all the methane released from the soil is concentrated at its surface.
The European satellite, on the other hand, requires sunlight to operate. He analyzed the atmosphere at altitudes of about five kilometers. Since the Martian atmosphere is turbulent during the day, methane dissipates to such an extent that it becomes elusive even for the thinnest instruments.
Experiments have shown that this is most likely the case. But another mystery remains: why does methane disappear on Mars during the day? Scientists have yet to answer this question.